Retrievable earth anchor

ABSTRACT

A retrievable earth anchor having a plurality of reinforced earth-engaging blades swingably mounted on a base assembly and extending through guide means in a manner that the blades are wedged in locking position when fully extended.

United States Patent [1 1 Ballew 1 Apr. 16, 1974 RETRIEVABLE EARTH ANCHOR [76] Inventor: Julius R. Ballew, PO. Box 1716,

Seminole, Tex. 79360 [22] Filed: June 6, 1973 [21] Appl. No.: 367,595

[52] US. Cl. 52/161, 52/12 [51] Int. Cl E02d 5/80 [58] Field of Search 52/160-164,

[56] References Cited UNITED STATES PATENTS l,0l5,611 l/l9l2 Bowen 52/l6l 10/1940 Handel 52/lbl 2,315,339 3/1943 Klein 2,490,465 12/ I 949 Ogburn 2,576,412 11/1951 Ogburn 52/I6l Primary Examiner-John E. Murtagh Attorney, Agent, or Firm-A. Yates Dowell, Jr.

57 ABSTRACT A retrievable earth anchor having a plurality of reinfonzedv earth-engaging blades swingably mounted on a base assembly and extending through guide means in a manner that the blades are wedged in locking position when fully extended.

4 Claims, 7 Drawing Figures PATENTEDAPRISIBM. 3.6031782 SHEETIUFZ WW AW PATENTEDAPRIGIEJM I 3803L782 saw e or 2 1 RETRIEVABLE EARTH ANCHOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to anchoring devices and specifically to retrievableearth anchors having expansible reinforced earth-engaging blades which are disposed outwardly of an anchor rod and there secured by a spreader plate which cooperates with the blades to increase the strength and durability of the anchor.

2. Description of the Prior Art Heretofore, there has been much effort directed to the design and construction of an earth anchor which could be easily utilized to provide support for the guy lines securing various poles, towers, mobile homes, and other structures. Due to'the many and varied uses of such anchors, a design was needed which could be used with a minimum of placement effort while at the same time had maximum strength and durability.

One particular type of anchor which provided increased strength and ease of placement was the expansible earth anchor. Two such anchors are disclosed in U.S. Pat. Nos. 2,576,412 to Ogburn and 930,486 to Lewis.

In order to increase the strength of expansion anchors, it became necessary to use reinforcedblades. However, stresses imparted to the bladesare not carried entirely by the blades, but are rather transferred, in part, to weaker portions of the anchor such as to the pivot pins on which the blades are-normally mounted or to various screw threaded members whereby damage to the threads can result. Therefore, in order to maximize the durability and strength of expansible earth anchors,- it is necessarythat the anchor blades, when placed under stress, be designed to cooperate with more durable parts of the anchor and thereby prevent possible damage to weaker parts. Other examples a of the prior art are US. Pat. Nos. 2,403,150 to Pieper and 2,217,271 to Handel.

SUMMARY OF THE INVENTION structure to become wedged in the U-s'haped guide bars of the guide plate. The blades also may be provided with an abutment which is disposed generally perpendicular to the length of the blade and adjacent the outer portion thereof and which cooperates with a blade retaining pin which protrudes from the U-shaped guide bars and prevents the blades from becoming disengaged from the guide plates.

It is an object of this invention to provide an expansible earth anchor having a blade structureand blade guiding and retaining plates which cause all the stress applied to the fully extended blades to be converted to a moment of forceabout the blade guiding and retaining plate and that portion of the blade having the maximum reinforcing and-thereby substantially increasing 2, the strength of the anchor while preventing damage to weaker parts thereof.

Another object of the invention is to provide an anchor which prevents the blades from becoming accidentally disengaged from the guiding and retaining plate.

A further object of the invention is to provide an expansible earth anchorhaving blades which are easily retracted from a fully extended position thereby allowing the anchor to be retrieved for further use.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustrating one application of the invention.

FIG. 2 is an enlarged vertical section illustrating the anchor in extended position.

FIG. 3is a side elevation illustrating the anchor in re-' tracted position.

FIG. 4 is an enlarged perspective of one of the blades.

FIG. 5 is a section taken on the line 5--5 of FIG. 2.

FIG. 6 is a section taken-on the line 6-6 of FIG. 2.

, FIG. 7 is a perspective similar to FIG. 4 showing a modified form of blade.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With continued reference .to the drawings, an expansible and retrievable earth anchor 10 is provided having a centrally disposed anchor rod 11. The anchor rod 11 may be of varying lengths depending upon the depth of placement necessary to insure that the bearing capacity of the earth above the expanded anchor is sufficient to prevent any, uprooting of the anchor. The anchor rod 11 has an elongated shaft 12 with screw threads at one end and a connecting portion 13 such as an eye at the other end through which guy lines and the like can be secured; Y

With reference to FIGS. 2, -3 and 6, a base member 14 is disposed along the screw-threaded portion of the shaft 12 and a nut 15, which threadedly engages the shaft 12,. is welded or otherwise attached to the base .member 14 to cause axial movement of the basemember along the shaft 12. Such base member has a plurality of pairs of .upwardly extending lugs or ears l6 and each pair of lugs receives a hinge pinvl7 disposed in a plane generally normal to the axis of the anchor rod 1 1.

An earth-engaging'blade 18 is connected to each of the pins 17 in such a manner as to allow the blades to move relative to the base member l'4. The blades 18 are curved outwardly along their length to allow the earth tobe easily penetrated as the blades are extended. In the preferred embodiment, the blades 18 have an outer substantially flat portion 19 and a reinforced curved inner portion 20 with concave-convex .surfaces. The reinforcing is provided by bending the edges of the blade downwardly and thereby forming flanges or locking members 21, although separate flanges could be welded or otherwise attached to the concave surface of the blade, as illustrated in FIG. 7.

The flanges 21 are formed in a generally triangular shape so that the maximum strength and the greatest size are located adjacent to the base of the blade 18.

A guiding and retaining plate or body 23 is mounted on the anchor rod 11 between the eye portion 13 and the base member 14. The body 23 has a central bore 24 which is of a sufficient diameter to allow such body to be freely rotatable about the anchor rod 11. An upper retaining collar 25 is secured to or formed as an integral part of the anchor rod above the body 23 to prevent upward vertical displacement of the plate along the anchor rod. ln order that the anchor can be retrieved from the ground, a pin 26 or other stop member is fixed to the anchor rod 11 below and adjacent to the body 23. The body 23 thus is capable of slight vertical movement while remaining free to rotate about the anchor rod.

The guiding and retaining plate or body 23 is constructed of a substantially flat steel plate to which a plurality of U-shaped guides 28 are welded or otherwise attached. Each of such guides includes a pair of generally parallel arms 29 connected to a bight portion 30 to form passageways through which the blades 18 pass. The bight portions 30 are located a predetermined 'distance from the body 23 and may be located at a slight downwardly inclined angle as shown best in FIG. 3.

The blades 18 are adapted to be wedged between the body 23 and the guides 28 and cooperate therewith in such a manner that the forces exerted on the blades when such blades are fully extended are carried entirely by the strongest portion of the blade and the guiding and retaining plate. With reference to FIGS. 2 and 3, when the base member 14 is moved upwardly, the blades are extended so that they project outwardly from the anchor rod until the increasingly larger flanges 21 cause the blades 18 to become wedged between the body 23 and bight portions 30 of the guides. When the blades are wedged, stresses on the blade are transmitted to the body 23 and guides 28 and substantially all force on the pins 17 is relieved.

In order to prevent the blades 18 from being accidentally withdrawn from the guides 28, a retaining bar 31 is welded or otherwise attached to the bight portion 30 of at least one of the U-shaped guides 28. Each of the retaining bars 31 extends inwardly toward the edge of the guiding and retaining plate orbody 23 and terminates in spaced relationship therewith. Also the retaining bars 31 are located between the flanges 21 of the blades to permit the blades to move through the guides 28. Cooperating with the retaining bars 31 are abutments or stops 33 which are welded to the underside of the outer portion 19 of the blade 18 in such a manner as to be substantially perpendicular to the longitudinal axis of the blade. Thus, as the blades are retracted through the guides 28, such blades have relatively free movement until the retaining bars 31 engage the abutment 33 and prevent further retraction of the blades.

ln the operation of the device, the anchor is placed in a bore hole in the earth with the blades in a retracted position, as shown in FIG. 3. When the anchor reaches the bottom of the bore hole, the rod 11 is rotated in a direction to cause the base member 14 to move upwardly toward the body 23 so that the blades 18 move through the guides 28 into the packed earth adjacent to the bore hole. Rotation of the anchor rod continues until the blades lock or become wedged between the guides 28 and the body 23. Because the blades are in wedged engagement, forces on the blades are not transferred inwardly of the areas of engagement with the body 23 and the guides 28. Thus, not only are substantially no forces transmitted to the hinges 17 or the base member 14, but the strength of the anchor is increased since the combined structural mass of the reinforcing flanges, the blades, the U-shaped guide means, and the guiding and retaining plate are capable of withstanding much greater stresses than they would if their cooperation were otherwise.

I claim:

1. A retrievable earth anchor comprising an anchor rod having connecting means at one end, at least a portion of said rod being screw-threaded, collar means fixed to said rod in spaced relationship to said connecting means, a body freely rotatably mounted on said anchor rod and having one surface adjacent to said collar means, a stop pin attached to said anchor rod adjacent to another surface of said body to restrict the vertical movement thereof, said body having a plurality of U- shaped guides extending outwardly therefrom, at least one of said U-shaped guides having a retaining bar fixed thereto and extending toward said body, a base member engaging the threaded portion of said anchor rod in axial spaced relationship to said body, said base member having a plurality of pairs of upstanding lugs, a hinge pin carried by each pair of lugs, each pin being disposed relatively closer to said anchor rod than are the U-shaped guides of said body, an arcuate earthengaging blade mounted on each of said hinge pins and extending through the U-shaped guides of said body, each blade being shaped to curve outwardly from said anchor rod, an abutment fixed to the concave side adjacent the outermost portion of the earth-engaging blades which extend through the U-shaped guides having said retaining bar attachedthereto, a pair of generally triangular reinforcing flanges along a portion of the concave side of each of said earth-engaging blades, said reinforcing flanges increasing in size from a point adjacent to the outermost portion of said earth-engaging blades to a point adjacent to said hinge pins, whereby rotation of said anchor rod in one direction moves said base member toward said body and causes said blades to move through said guides into the earth until the blades are wedged between said guides and said body so that substantially all of the stress on each of said blades acts as a moment of force about the points at which said blades are wedged thus supporting the stress on said earth-engaging blades at a point of maximum strength.

2. In an expansible earth anchor having an anchor rod with connecting means at one end, a portion of said rod being screw-threaded, collar means on said rod in spaced relation to said connecting means, a body freely rotatably mounted on said anchor rod and having one surface adjacent said collar means, said body having a plurality of guide means spaced from said rod and forming enclosed passageways, a base member threadedly engaging said anchor rod in axial spaced relationship to said body, said base member having a plurality of hinge means, each of said hinge means being disposed relatively closer to said anchor rod than are said guide means, an earth-engaging blade having concavoconvex surfaces swingably mounted on each of said hinge means and extending through said passageways of the U-shaped guides of said body, each blade being shaped to curve outwardly away from said anchor rod, the improvement comprising a pair of generally triangular reinforcing flanges along a portion of the concave surface of each of said earth-engaging blades, said reinforcing flanges increasing in size from a point adjacent the outermost portion of said earth-engaging blades to a point adjacent said hinge means, whereby rotation of said rod in one direction moves said base member toward said bodyand causes said blades to be wedged between said body and said guides so that substantially all stresses on each of said blades act as a moment of force about the point at which said blades are wedged with said body thus supporting the stresses on said earth-engaging blades at a point of maximum strength.

3. The structure of claim 2 in which at least one of said guide means includes a retaining bar fixed thereto which extends toward said body, and an abutment fixed to the concave surface of at least one of said blades in a position to engage said retaining bar, whereby the blades are maintained within said guides.

4. The structure of claim 2 in which a stop pin is mounted on said anchor rod adjacent to said body and between said base member and said body, whereby said body is maintained in substantially'fixed axial position on said rod and cooperates with said base member to cause said earth-engaging blades to be retracted from an extended position. 

1. A retrievable earth anchor comprising an anchor rod having connecting means at one end, at least a portion of said rod being screw-threaded, collar means fixed to said rod in spaced relationship to said connecting means, a body freely rotatably mounted on said anchor rod and having one surface adjacent to said collar means, a stop pin attached to said anchor rod adjacent to another surface of said body to restrict the vertical movement thereof, said body having a plurality of U-shaped guides extending outwardly therefrom, at least one of said U-shaped guides having a retaining bar fixed thereto and extending toward said body, a base member engaging the threaded portion of said anchor rod in axial spaced relationship to said body, said base member having a plurality of pairs of upstanding lugs, a hinge pin carried by each pair of lugs, each pin being disposed relatively closer to said anchor rod than are the U-shaped guides of said body, an arcuate earth-engaging blade mounted on each of said hinge pins and extending through the U-shaped guides of said body, each blade being shaped to curve outwardly from said anchor rod, an abutment fixed to the concave side adjacent the outermost portion of the eartH-engaging blades which extend through the Ushaped guides having said retaining bar attached thereto, a pair of generally triangular reinforcing flanges along a portion of the concave side of each of said earth-engaging blades, said reinforcing flanges increasing in size from a point adjacent to the outermost portion of said earth-engaging blades to a point adjacent to said hinge pins, whereby rotation of said anchor rod in one direction moves said base member toward said body and causes said blades to move through said guides into the earth until the blades are wedged between said guides and said body so that substantially all of the stress on each of said blades acts as a moment of force about the points at which said blades are wedged thus supporting the stress on said earth-engaging blades at a point of maximum strength.
 2. In an expansible earth anchor having an anchor rod with connecting means at one end, a portion of said rod being screw-threaded, collar means on said rod in spaced relation to said connecting means, a body freely rotatably mounted on said anchor rod and having one surface adjacent said collar means, said body having a plurality of guide means spaced from said rod and forming enclosed passageways, a base member threadedly engaging said anchor rod in axial spaced relationship to said body, said base member having a plurality of hinge means, each of said hinge means being disposed relatively closer to said anchor rod than are said guide means, an earth-engaging blade having concavo-convex surfaces swingably mounted on each of said hinge means and extending through said passageways of the U-shaped guides of said body, each blade being shaped to curve outwardly away from said anchor rod, the improvement comprising a pair of generally triangular reinforcing flanges along a portion of the concave surface of each of said earth-engaging blades, said reinforcing flanges increasing in size from a point adjacent the outermost portion of said earth-engaging blades to a point adjacent said hinge means, whereby rotation of said rod in one direction moves said base member toward said body and causes said blades to be wedged between said body and said guides so that substantially all stresses on each of said blades act as a moment of force about the point at which said blades are wedged with said body thus supporting the stresses on said earth-engaging blades at a point of maximum strength.
 3. The structure of claim 2 in which at least one of said guide means includes a retaining bar fixed thereto which extends toward said body, and an abutment fixed to the concave surface of at least one of said blades in a position to engage said retaining bar, whereby the blades are maintained within said guides.
 4. The structure of claim 2 in which a stop pin is mounted on said anchor rod adjacent to said body and between said base member and said body, whereby said body is maintained in substantially fixed axial position on said rod and cooperates with said base member to cause said earth-engaging blades to be retracted from an extended position. 